The small RNA ErsA of Pseudomonas aeruginosa, transcribed from the same genomic context of the well-known Escherichia coli Spot 42, has been characterized. We show that, different from Spot 42, ErsA is under the transcriptional control of the envelope stress response, which is known to impact the pathogenesis of P. aeruginosa through the activity of the alternative sigma factor σ22. The transcriptional responsiveness of ErsA RNA also spans infection-relevant cues that P. aeruginosa can experience in mammalian hosts, such as limited iron availability, temperature shifts from environmental to body temperature, and reduced oxygen conditions. Another difference between Spot 42 and ErsA is that ErsA does not seem to be involved in the regulation of carbon source catabolism. Instead, our results suggest that ErsA is linked to anabolic functions for the synthesis of exoproducts from sugar precursors. We show that ErsA directly operates in the negative post-transcriptional regulation of the algC gene that encodes the virulence-associated enzyme AlgC, which provides sugar precursors for the synthesis of several P. aeruginosa polysaccharides. Like ErsA, the activation of algC expression is also dependent on σ22. Altogether, our results suggest that ErsA and σ22 combine in an incoherent feed-forward loop to fine-tune AlgC enzyme expression.
Post-transcriptional regulation of the virulence-associated enzyme AlgC by the σ22-dependent small RNA ErsA of Pseudomonas aeruginosa / S. Ferrara, S. Carloni, R. Fulco, M. Falcone, R. Macchi, G. Bertoni. - In: ENVIRONMENTAL MICROBIOLOGY. - ISSN 1462-2912. - 17:1(2015 Jan), pp. 199-214.
|Titolo:||Post-transcriptional regulation of the virulence-associated enzyme AlgC by the σ22-dependent small RNA ErsA of Pseudomonas aeruginosa|
FERRARA, SILVIA (Primo)
CARLONI, SARA (Secondo)
MACCHI, RAFFAELLA ADA (Penultimo)
BERTONI, GIOVANNI (Ultimo)
|Parole Chiave:||pseudomonas aeruginosa; bacterial small RNAs; post-transcriptional regulation; Spot 42; envelope stress; σ22; AlgT/U; Hfq; exopolysaccharide; AlgC; D-cycloserine; incoherent feed-forward loop|
|Settore Scientifico Disciplinare:||Settore BIO/18 - Genetica|
Settore BIO/19 - Microbiologia Generale
|Data di pubblicazione:||gen-2015|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1111/1462-2920.12590|
|Appare nelle tipologie:||01 - Articolo su periodico|